In this study, using the plasma spray method, tensile and compression fatigue tests are performed in saline solution to examine the effect of Ti undercoat on corrosion fatigue behavior of alumina-coated specimens. The alumina-coated material using Ti in the undercoat shows better corrosion fatigue strength than the base material in the entire stress amplitude range. Fatigue cracking of UT specimens occurs in the recess formed by grit-blasting treatment and progresses toward the base metal. Subsequently, the undercoat is destroyed at a stage where the deformation of the undercoat cannot follow the crack opening displacement. The residual stress of the UT specimen has a tensile residual stress up to about 100 μm below the surface of the base material; however, when the depth exceeds 100 μm, the residual stress becomes a compressive residual stress. In addition, the inside of the spray coating film is compressive residual stress, which contributes to improving the fatigue strength characteristics. A hardened layer due to grit-blasting treatment is formed near the surface of the UT specimen, contributing to the improvement of the fatigue strength characteristics. Since the natural potential of Ti spray coating film is slightly higher than that of the base material, it exhibits excellent corrosion resistance; however, when physiological saline intrudes, a galvanic battery is formed and the base material corrodes preferentially.

Abstract
1.서 론
2. 실험방법
    2.1 시편의 코팅처리 및 코팅막 특성
    2.2 전기화학적 특성
    2.3 피로시험과 조직관찰
3. 실험결과 및 고찰
    3.1 피로강도 특성
    3.2 단면의 미세구조 해석
    3.3 파단면의 미세구조 해석
    3.4 시편 단면에 대한 경도분포 및 잔류응력
4.결 론
References

• 한창석(호서대학교 자동차ICT공학과) | Chang-Suk Han (Dept. of ICT Automotive Engineering, Hoseo University) Corresponding author
• 김우석(호서대학교 자동차ICT공학과) | Woo-Suk Kim (Dept. of ICT Automotive Engineering, Hoseo University)